Hawk Engineering builds some of his rigs with a garage under the bedroom, has a fold down ramp on the back, room for two bikes. Not too bad if you do not need or want a stand up bedroom. He does have a standard receiver hitch under the back not sure how much weight capacity it has.
Jason has a used one on his site that has been for sale for a long time.
https://www.hawkengineering.com/4509gcddgta0csb.html. This is one of his earlier conversions that the owner upgraded to a new one on. (price has come down a bunch as well, to bad it would not work for us.
We have a big harley touring bike, and it will not fit in a side loading garage as it is longer than a 102" wide coach body. With a rear door garage that's a lot of overhang.
That leaves us with either the full garage on top of the frame rails with a lift gate similar to Haulmark or Showhauler, or designing something custom. Leaning toward the custom route as we do not want to give up that much interior space to a full garage.
Frodaddy has a thread going in the "building your own" section of the forum,
http://www.truckconversion.net/forum...w-hauler-3962/ He has built his own rig with a side door garage on a KW-900. Lots of pics and a great looking rig.
Good luck,
Dave